F. Chris Minion, M. S., PhD. received his doctorate in December, 1983 from the University of Alabama at Birmingham where he majored in Cellular and Molecular Biology in the Department of Microbiology. His research focused on Mycoplasma pulmonis as a model system for in vitro analysis of potential mycoplasmal virulence factors. Following his graduate studies, he completed a postdoctoral research assistantship in Bacterial Genetics on temperature regulation of plasmic borne calcium response genes of Yersinia pestis. Dr. Minion received a New Investigator Award from the N. I. H. (April l, 1986) which was successfully renewed July 1, l989, and accepted a tenure track faculty appointment in the Department of Veterinary Microbiology and Preventive Medicine at the Veterinary Medical Research Institute, Iowa State University (June 1, 1986). Dr. Minion's long-range goal is to characterize the genetic and biochemical mechanisms in pathogenesis of mycoplasmal diseases. The model system employed for these studies is Mycoplasma pulmonis, a respiratory and genital tract pathogen of laboratory rodents. Dr Minion's research efforts in mycoplasmal pathogenesis have been focused in two areas: surface components with virulence potential, and development of genetics systems to use in the study of these components. His contributions to this field include the identification of multiphasic binding activities of M. pulmonis, the identification of a membrane-bound hemolysin and nuclease in M. pulmonis, the characterization and optimization of a polyethylene glycol transformation procedure for M. pulmonis, the first use of Tn4001 in mycoplasmas, the development of an integrative vector shuttle system between Escherichia coli and M. pulmonis, and the characterization of high frequency genetic exchange in M. pulmonis. Future studies will focus on the identification and characterization of virulence-related surface activities(our immediate focus will be on the membrane nuclease and hemolysin proteins); the construction of genetic mutants to assess the contribution of specific membrane-related activities to virulence; the fine structure mapping, sequence analysis, and regulation of mycoplasmal promoters; the construction of chromosomal and genetic maps of M. pulmonis; and the study of genetic exchange in mycoplasmas and how it relates to antigenic variation and pathogenesis. This award will allow continued progress toward these goals by providing Dr Minion with sufficient opportunity for research, by reducing future teaching responsibilities, and by ensuring continued support by Iowa State University, College of Veterinary Medicine for his program. The University's commitment to long-range health-related research remains firm as evidenced by the continued support for the Veterinary Medical Research Institute and its commitment to Dr. Minion with technical support and release time for research.